At the WTA Finals in Singapore, defending champion Caroline Wozniacki beat Petra Kvitova with a 7-5 3-6 6-2 victory.

The 28 years old, Denmark's Wozniacki has beaten Kvitova for the first time in four years.

Her last win over the Czech fourth seed came at the 2014 WTA Finals.

The WTA Finals feature the leading eight players this year, split into two groups of four.

The top two players from each round-robin group will progress to the semi-finals, with the final on Sunday.